Thanks Stefan,

I have looked at that sample, but I have some unique requirements, and looks like a chart would do what I'd like it to do.  In any case, in a different part of the application, I will be using a chart with a custom series that also has labels, and I am still not clear how to map the values to the label values and get  them scaled to grid coordinates inside the RenderSeriesOverride method.

Obviously something in the CategoryXAxis is mapping a coordinate to the string value of the label, and I'd like to know how I can get to that logic.

Thanks!

Hi Stefan,

The arguments of those functions take a double.  This is precisely my problem.  Since my data is label based, I don't have a double value.  When I set the CategoryXAxis.ItemsSource, the collection contains only string values, and I need to match those string values to my data.

For example:

My chart consists of the following axis:

XAxis : red, yellow, green
YAxis : orange, pear, apple 

apple   |
pear    |
orange |_______________________ 

               red   yellow    green

My datapoints are:

{ red, apple }
{ yellow, pear }
{ green, orange }

The resulting plot should be:

apple   |   X
pear    |              X
orange |_________________X_____ 

               red   yellow    green

Now to plot { red, apple }, I somehow need to resolve red to a coordinate of the grid.  When I initially passed in my values to the CategoryXAxis [red, yellow, green], somehow they got plotted on coordinates 0, 1, and 2.

So how do I get the coordinate of where { red, apple } goes?  I can't pass in XAxis.GetScaledValue(red, params), as it is not a double.

How did the CategoryXAxis figure out where red should be in the first place?  Shouldn't I have some value mapping function that will match my data type to where it belongs?  Clearly the other grids can somehow do this.

I have gotten around the above problem by creating a custom mapping of the coordinates based on their index, and providing a custom function to resolve the datapoints based on their property values that match the current labels.

I'd still like to know if there is a better way to do this.  How do the bar charts do it?

Also, how can I center my labels like in the bar chart, and not have them appear at the tick marks?  

Here is a picture of what I'm trying to do:

I have data points:

[A, 1]
[B, 2]
[B, 3]
[C, 4] 

Items source is set to my collection of datapoints, and I'd like the chart to show the following:

Hello,

Thank you for your feedback. I am glad that you resolved your issue and I believe that other community members may benefit from this as well.

Thanks again.

Thank you! That answers my label centering question!

Hello,

I have created a sample project for you where I centered the horizontal labels using DataTemplate for the Label. I bound its RenderTransform and translate it based on the grid lines. You can follow the same approach for the vertical labels.

Hope this helps you.

This example illustrates centered X axis labels in the first bar chart:

http://ko.infragistics.com/products/wpf/sample/data-chart/axis-types

However, with my custom series, when I apply CategoryXAxis and CategoryYAxis, my values still appear at the tick marks, like the NumericXAxis instead of centered.  How can I get my labels to be centered like it is shown in the bar chart?

Unfortunately that doesn't help me.  Perhaps I shouldn't have said Heatmap, as the "heatmap" I'm trying to create is rather unique, with some unique requirements.  

I just need to know how to center the labels between tickmarks on a chart.  The chart with a custom series allows me to do what I need, but these minor issues are becoming a limiting factor.  I can't see why it wouldn't be possible to center the labels between each tickmark, as the bar chart does it.